This proposal extends our previous research concerning the neurobehavioral outcome of closed head injury (CHI) in children by addressing the relationship of frontal lobe lesions to recovery. We postulate that frontal lobe injury increases the likelihood of impaired reasoning and concept formation, disrupts use of mnemonic strategies, reduces productivity on verbal and visuospatial fluency measures, results in disinhibition and interferes with motor sequencing and motor responses which conflict with the examiner's behavior. Moreover, we postulate that frontal lobe lesions result in more severe behavioral disturbance as compared to children sustaining extrafrontal lesions or diffuse injury. Study I is a cross-sectional investigation of three age cohorts (0-4, 5-10, 11-15 years at the time of injury) who had been hospitalized for moderate to severe CHI (n=192) at least three years prior to testing. All patients will undergo magnetic resonance imaging (MRI) to characterize the presence and localization of focal brain lesions. Based on the results of MRI, the patients will be classified as having (1) frontal lobe lesions; (2) extrafrontal lesions; (3) frontal/extrafrontal overlap; (4) diffuse brain insult. Study II is a longitudinal design in which prospective pediatric admissions (n=120) for moderate or severe CHI-are i recruited into 3 age cohorts (5-7 years, 8-10 years, 11-15 years at the time of injury) and the same localization of lesion groups as in Study I. Study II evaluates the relationship between localization of brain lesion (according to MRI at 3 months) and neurobehavioral changes over 3 years as measured in examinations at baseline (i.e., ,,when posttraumatic amnesia resolves), 3, 6, 12, 21, and 36 months postinjury. Children sustaining mild CHI will serve as a comparison group in Studies I (n=60) and II (n=36). All children will undergo testing of problem solving, memory strategy, motor function, fluency and evaluation of discourse in 5 narratives. Several control tests (e.g naming) will be given to evaluate the specificity of deficits associated with frontal lesions. Psychosocial adjustment and behavior will also be studied. Study I data will be analyzed using the General Linear Model (GLM) approach to address the specific aims, including the relationship between frontal lobe lesions and neurobehavioral recovery. The data collected in Study II will be analyzed using a GLM approach as well as multi-level modeling of growth curves to assess changes in development which are related to the localization of brain lesion and age at injury.